Colonic adenocarcinoma arising from traditional serrated adenoma.

We report the case of a 59-year-old male who underwent a screening colonoscopy after a positive fecal occult blood test. Several polyps were removed during the colonoscopy: two pedunculated tubular adenomas of 7 mm, a tubular adenoma with high-grade dysplasia of 25 mm and a pedunculated polyp of 20 mm in the descending colon. Histopathological analysis of the pedunculated polyp revealed a well-differentiated adenocarcinoma (G1) with a mucinous component that invaded the submucosa (T1). The resection margins were less than 1 mm, lymphovascular invasion was present and high budding (10 or more) with an invasive component of 8 mm.